Doing a short story with Chris or Stacia going to a high school reunion would be hilarious.
There are a number of characters we’ve been introduced to through out the series that have vanished. It would be interesting to get the reaction that Chris’s neighbors from book 1 would have to him if they ran into him now. Whatever happened to the various officers Chris worked with? A reunion of those characters might be a fun aside. Declan had a number of friends from high school we haven’t seen again. I think Rory getting a job at VAMP might be a thing.
One character that has been very prominent and we have almost no back story on is Delwood. I’ve read through the series more times than I’ll admit to and I don’t think we know what pack he’s from or much of anything. I think some background on his family would be very interesting.